With the improvement of living standards, the life philosophy of being distinctive, fashionable, healthy, and environmentally friendly becomes popular, and fashionable and environmentally friendly articles for daily use and vehicles are favored by more and more people. Bicycles and foldable electric vehicles evolve from being only a means of transport to being a symbol of a fashionable and healthy lifestyle, and are a means for practicing environmental protection. The increasingly popular foldable bicycle or foldable electric vehicle is characterized in saving storage room and being convenient to carry, as the volume of the bicycle after being folded is smaller than one fifth of a common bicycle. Since the bicycle is small and light, it is easy to be carried up and down stairs, into and out of an elevator, and into a bus or metro train. Furthermore, the foldable bicycle is pleasant to look at, and shows exquisite workmanship, thereby making it top equipment of fashion people.
However, in the existing foldable bicycle or foldable electric vehicle, the frame or the connecting mechanism used for connecting the front and rear frames has a complex structure, which contains multiple parts, is time and energy consuming when being folded, and is inconvenient to operate.
Therefore, it is in urgent need of a telescopic frame which is applicable to a foldable bicycle or foldable electric vehicle, has a simple structure, and is capable of being automatically folded.